package main.service;

import main.service.EnterpriseMailBean;

import javax.mail.*;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;
import javax.mail.internet.MimeUtility;
import javax.mail.search.AndTerm;
import javax.mail.search.ComparisonTerm;
import javax.mail.search.SearchTerm;
import javax.mail.search.SentDateTerm;
import java.io.*;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Properties;

public class EmailUtils {
	public static String SAVE_DIR;
    public static boolean NEED_SAVE_DIR;
    // = "qintianshu@jspdi.com.cn"
    public static String ACCOUNT;
    //  = "Qts970516"
    public static String PASSWORD;
    // 2021-11-05
    public static String START_TIME;

    public static List<EnterpriseMailBean> readEmailPop() throws Exception {
        Properties props = new Properties();
        props.put("mail.pop3.host", "pop.exmail.qq.com");
        props.put("mail.pop3.auth", "true");
        props.setProperty("mail.store.protocol", "pop3");
        props.put("mail.pop3.starttls.enable", "true");
        Session session = Session.getInstance(props);
        Store store = session.getStore("pop3");
        store.connect("pop.exmail.qq.com", ACCOUNT, PASSWORD);
        //Folder folder = store.getFolder("Inbox");
        Folder defaultFolder = store.getDefaultFolder();
        Folder[] allFolder = defaultFolder.list();
        Folder folder= store.getFolder("INBOX");
        //邮箱打开方式
        folder.open(Folder.READ_WRITE);
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
        //开始时间
        Date startDate = simpleDateFormat.parse(START_TIME);
        // 结束时间
        Date endDate = new Date();
        //开始时间的邮件
        SearchTerm comparisonTermGe = new SentDateTerm(ComparisonTerm.GE, startDate);
        SearchTerm comparisonTermLe = new SentDateTerm(ComparisonTerm.LE, endDate);
        SearchTerm comparisonAndTerm = new AndTerm(comparisonTermGe, comparisonTermLe);
        //条件查询只能通过pop协议的方式才生效
        Message[] messages = folder.search(comparisonAndTerm);
        //  Message[] messages = folder.getMessages();
        System.out.println("读取的邮件总数: " + messages.length);
        return parseFileMessage(messages);
    }

    public static List<EnterpriseMailBean> parseFileMessage(Message... messages) throws Exception {
        ArrayList<EnterpriseMailBean> enterpriseMailBeans = new ArrayList<>();
        if (messages == null || messages.length < 1) {
            System.out.println("没有可读取邮件");
            return enterpriseMailBeans;
        }
        // 解析读取到的邮件
        int i = 0;
        for (Message message : messages) {
            i++;
            MimeMessage msg = (MimeMessage) message;
            String subject = MimeUtility.decodeText(msg.getSubject());
            EnterpriseMailBean enterpriseMailBean = new EnterpriseMailBean();
            enterpriseMailBean.subject = subject;
            enterpriseMailBean.sender = getFrom(msg);
            enterpriseMailBean.receiveAddress = getReceiveAddress(msg, null);
            enterpriseMailBean.sentDate = getSentDate(msg, null);
            enterpriseMailBean.date = msg.getSentDate();
            enterpriseMailBean.priority = getPriority(msg);
            enterpriseMailBean.size = msg.getSize() / 1024 + "kb";
            enterpriseMailBeans.add(enterpriseMailBean);

            if (!NEED_SAVE_DIR)
                continue;
            System.out.println("是否已读：" + isSeen(msg));
            System.out.println("是否需要回执：" + isReplySign(msg));
            StringBuffer content = new StringBuffer(30);

            if (subject.contains("?"))
                subject = subject.replace("?", "");
            message.writeTo(new FileOutputStream(new File(EmailUtils.SAVE_DIR + "/" + subject + ".eml")));

            getMailTextContent(msg, content);
            WUtil.writeStringToFile(content.toString(), MimeUtility.decodeText(msg.getSubject()));
//            System.out.println("邮件正文：" + (content.length() > 100 ? content.substring(0,100) + "..." : content));
            System.out.println("邮件正文：" + content);

            System.out.println();
            boolean isContainerAttachment = isContainAttachment(msg);
            System.out.println("是否包含附件：" + isContainerAttachment);
            if (isContainerAttachment) {
                saveAttachment(msg, SAVE_DIR + "\\", msg.getFileName()); //保存附件
//                saveAttachment(msg, SAVE_DIR, msg.getFileName()); //保存附件
            }
//            System.out.println("------------------第" + msg.getMessageNumber() + "封邮件解析结束-------------------- ");
            System.out.println("------------------第" + i + "封邮件解析结束-------------------- ");
        }
        return enterpriseMailBeans;
    }

    /**
     * 获得邮件发件人
     *
     * @param msg 邮件内容
     * @return 姓名 <Email地址>
     * @throws MessagingException
     * @throws UnsupportedEncodingException
     */
    public static String getFrom(MimeMessage msg) throws MessagingException, UnsupportedEncodingException {
        String from = "";
        Address[] froms = msg.getFrom();
        if (froms.length < 1)
            throw new MessagingException("没有发件人!");
        InternetAddress address = (InternetAddress) froms[0];
        String person = address.getPersonal();
        if (person != null) {
            person = MimeUtility.decodeText(person) + " ";
        } else {
            person = "";
        }
        from = person + "<" + address.getAddress() + ">";

        return from;
    }

    /**
     * 获得邮件发送时间
     *
     * @param msg 邮件内容
     * @return yyyy年mm月dd日 星期X HH:mm
     * @throws MessagingException
     */
    public static String getSentDate(MimeMessage msg, String pattern) throws MessagingException {
        Date receivedDate = msg.getSentDate();
        if (receivedDate == null)
            return "";

        if (pattern == null || "".equals(pattern))
            pattern = "yyyy年MM月dd日 E HH:mm ";

        return new SimpleDateFormat(pattern).format(receivedDate);
    }

    /**
     * 判断邮件是否已读
     *
     * @param msg 邮件内容
     * @return 如果邮件已读返回true, 否则返回false
     * @throws MessagingException
     */
    public static boolean isSeen(MimeMessage msg) throws MessagingException {
        return msg.getFlags().contains(Flags.Flag.SEEN);
    }

    /**
     * 判断邮件是否需要阅读回执
     *
     * @param msg 邮件内容
     * @return 需要回执返回true, 否则返回false
     * @throws MessagingException
     */
    public static boolean isReplySign(MimeMessage msg) throws MessagingException {
        boolean replySign = false;
        String[] headers = msg.getHeader("Disposition-Notification-To");
        if (headers != null)
            replySign = true;
        return replySign;
    }

    /**
     * 获得邮件的优先级
     *
     * @param msg 邮件内容
     * @return 1(High):紧急  3:普通(Normal)  5:低(Low)
     * @throws MessagingException
     */
    public static String getPriority(MimeMessage msg) throws MessagingException {
        String priority = "普通";
        String[] headers = msg.getHeader("X-Priority");
        if (headers != null) {
            String headerPriority = headers[0];
            if (headerPriority.contains("1") || headerPriority.contains("High"))
                priority = "紧急";
            else if (headerPriority.contains("5") || headerPriority.contains("Low"))
                priority = "低";
            else
                priority = "普通";
        }
        return priority;
    }

    /**
     * 根据收件人类型，获取邮件收件人、抄送和密送地址。如果收件人类型为空，则获得所有的收件人
     * <p>Message.RecipientType.TO  收件人</p>
     * <p>Message.RecipientType.CC  抄送</p>
     * <p>Message.RecipientType.BCC 密送</p>
     *
     * @param msg  邮件内容
     * @param type 收件人类型
     * @return 收件人1 <邮件地址1>, 收件人2 <邮件地址2>, ...
     * @throws MessagingException
     */
    public static String getReceiveAddress(MimeMessage msg, Message.RecipientType type) throws MessagingException {
        StringBuilder receiveAddress = new StringBuilder();
        Address[] addresss;
        if (type == null) {
            addresss = msg.getAllRecipients();
        } else {
            addresss = msg.getRecipients(type);
        }

        if (addresss == null || addresss.length < 1)
            return ACCOUNT;
//            throw new MessagingException("没有收件人!");
        for (Address address : addresss) {
            InternetAddress internetAddress = (InternetAddress) address;
            receiveAddress.append(internetAddress.toUnicodeString()).append(",");
        }
        receiveAddress.deleteCharAt(receiveAddress.length() - 1); //删除最后一个逗号
        return receiveAddress.toString();
    }

    /**
     * 判断邮件中是否包含附件
     *
     * @return 存在附件返回true，不存在返回false
     */
    public static boolean isContainAttachment(Part part) throws Exception {
        boolean flag = false;
        if (part.isMimeType("multipart/*")) {
            MimeMultipart multipart = (MimeMultipart) part.getContent();
            int partCount = multipart.getCount();
            for (int i = 0; i < partCount; i++) {
                BodyPart bodyPart = multipart.getBodyPart(i);
                String disp = bodyPart.getDisposition();
                if (disp != null && (disp.equalsIgnoreCase(Part.ATTACHMENT) || disp.equalsIgnoreCase(Part.INLINE))) {
                    flag = true;
                } else if (bodyPart.isMimeType("multipart/*")) {
                    flag = isContainAttachment(bodyPart);
                } else {
                    String contentType = bodyPart.getContentType();
                    if (contentType.contains("application")) {
                        flag = true;
                    }

                    if (contentType.contains("name")) {
                        flag = true;
                    }
                }

                if (flag) break;
            }
        } else if (part.isMimeType("message/rfc822")) {
            flag = isContainAttachment((Part) part.getContent());
        }
        return flag;
    }

    /**
     * 保存文件
     *
     * @param destDir  文件目录
     * @param fileName 文件名
     * @throws Exception 异常
     */
    public static void saveAttachment(Part part, String destDir, String fileName) throws Exception {
        if (part.isMimeType("multipart/*")) {
            //复杂体邮件
            Multipart multipart = (Multipart) part.getContent();
            //复杂体邮件包含多个邮件体
            int partCount = multipart.getCount();
            for (int i = 0; i < partCount; i++) {
                //获得复杂体邮件中其中一个邮件体
                BodyPart bodyPart = multipart.getBodyPart(i);
                //迭代处理邮件体，直到附件为止
                String disp = bodyPart.getDisposition();
                String decodeName = decodeText(bodyPart.getFileName());
                decodeName = decodeName==null ? fileName : decodeName;
                if (disp != null && (disp.equalsIgnoreCase(Part.ATTACHMENT) || disp.equalsIgnoreCase(Part.INLINE))) {
                    saveFile(bodyPart.getInputStream(), destDir, decodeName);
                } else if (bodyPart.isMimeType("multipart/*")) {
                    saveAttachment(bodyPart, destDir, fileName);
                } else {
                    String contentType = bodyPart.getContentType();
                    if (contentType.contains("name") || contentType.contains("application")) {
                        saveFile(bodyPart.getInputStream(), destDir, decodeName);
                    }
                }
            }
        } else if (part.isMimeType("message/rfc822")) {
            saveAttachment((Part) part.getContent(), destDir, fileName);
        }
    }

    /**
     * 获得邮件文本内容
     *
     * @param part    邮件体
     * @param content 存储邮件文本内容的字符串
     * @throws MessagingException
     * @throws IOException
     */
    public static void getMailTextContent(Part part, StringBuffer content) throws MessagingException, IOException {
        //如果是文本类型的附件，通过getContent方法可以取到文本内容，但这不是我们需要的结果，所以在这里要做判断
        boolean isContainTextAttach = part.getContentType().indexOf("name") > 0;
        if (part.isMimeType("text/*") && !isContainTextAttach) {
            content.append(part.getContent().toString());
        } else if (part.isMimeType("message/rfc822")) {
            getMailTextContent((Part) part.getContent(), content);
        } else if (part.isMimeType("multipart/*")) {
            Multipart multipart = (Multipart) part.getContent();
            int partCount = multipart.getCount();
            for (int i = 0; i < partCount; i++) {
                BodyPart bodyPart = multipart.getBodyPart(i);
                getMailTextContent(bodyPart, content);
            }
        }
    }

    /**
     * 读取输入流中的数据保存至指定目录
     *
     * @param is       输入流
     * @param fileName 文件名
     * @param destDir  文件存储目录
     */
    private static void saveFile(InputStream is, String destDir, String fileName)
            throws Exception {
        createEmptyDirectory(destDir);
        BufferedInputStream bis = new BufferedInputStream(is);
        BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(new File(destDir + fileName)));
        int len;
        while ((len = bis.read()) != -1) {
            bos.write(len);
            bos.flush();
        }
        bos.close();
        bis.close();
    }

    /**
     * 创建一个空目录
     */
    public static void createEmptyDirectory(String directoryPath) {
        File file = new File(directoryPath);
        if (!file.exists()) {
            file.mkdirs();
        }
    }

    /**
     * 文本解码
     */
    public static String decodeText(String encodeText) throws Exception {
        if (encodeText == null || "".equals(encodeText)) {
            return "";
        } else {
            return MimeUtility.decodeText(encodeText);
        }
    }
}
